For posterity here is that custard being thrown at Lord Mandelson. Perhaps better entertainment however was Mandy's response: "I quite like custard, just not when its thrown in my face." Bizarrly, the custard thrower has only this afternoon been arrested after she walked away form the scene unapprehended to carry out a series of media interviews. Efficiency cuts at the Met may have been a little too savage?
Her cause is of course Heathrow, or rather stopping its future expansion. Noble, but best served by words rather than custard.